We're working on a 55 300 and it has the old school red oxide primer. It has a few areas that need patches but I'm astonished at how little surface rust is under areas with original paint/primer and how much more is under the areas that have been spot repaired. Not every job is gonna get stripped and sometimes I'd rather leave the factory zinc coating on the car along with at least the original primer.

In the case of a 1955 car, I would take it the car down to bare metal or I wouldn't touch it, zinc primer, how little surface rust there is under the original paint/primer....I don't want to get picky but you yourself said how "little" surface rust is under the areas with original paint/primer....then it's not surface rust...it's rust underneath...the car is 58 years old...if there's a little rust...it's got to be cleaned up or it will come through. Products today are much more apt to minimize rust than they where 50 to 60 years ago, wouldn't you agree? Why, when doing a restoration would you want to start a foundation on 60 year old technology?

most times the baked on paint from the factory is a better base than going to metal and starting over.. depends on the car..
if it's a laquer paint on a all original car, I'd go to metal.. cause if it hasn't spiderwebed(checked) it will...
got to remember mid 80's and newer are 26+ years old now..
tons of these are getting rodded, as most don't have the green for the 64-72 cars,, or s 32-34 ford.. 55-57 etc..
myc-10(71) will go to metal, as the new paint buy the p/o (2000) lifted the oem paint, but not the primer under it.. no idea what gm used on trucks in 71 (enamel??) but the mid line duport pulled it up.. 30 years later.. if it was the new paint only lifting, I'd say p/o prep was the cause.. but it pulled the factory paint.. no sealer was used as far as I can tell.. from a d/a and feathering a spot[/QUOT

Factory paint is baked on...this is done to keep the assembly line moving...Body Shops that have an air make up unit with their booth also bake their paint to keep the production moving. Baking paint doesn't make paint better...paint will cure over time and be as strong as unbaked paint.

I'm sorry, I'd like to respond to the rest of your post but, maybe it's the fact that I don't understand all acronyms, I'm not sure but, I am having trouble understanding what you are trying to say. If you could help me out with what "p/o prep" means....does the p/o stand for pour overall?

most times the baked on paint from the factory is a better base than going to metal and starting over.. depends on the car..
if it's a laquer paint on a all original car, I'd go to metal.. cause if it hasn't spiderwebed(checked) it will...
got to remember mid 80's and newer are 26+ years old now..
tons of these are getting rodded, as most don't have the green for the 64-72 cars,, or s 32-34 ford.. 55-57 etc..
myc-10(71) will go to metal, as the new paint buy the p/o (2000) lifted the oem paint, but not the primer under it.. no idea what gm used on trucks in 71 (enamel??) but the mid line duport pulled it up.. 30 years later.. if it was the new paint only lifting, I'd say p/o prep was the cause.. but it pulled the factory paint.. no sealer was used as far as I can tell.. from a d/a and feathering a spot

a good case and point is if say a 2000 Jetta was vandalized and keyed all around. The shop upsales a complete paint job for a few hundred more out of the customer's pocket plus what insurance is giving. You'd want to feather anything to metal like rock chips/keyed areas but you DO NOT want to go taking off that factory zinc coating by stripping the car, that's just stupid if you ask me.

I do not agree that a clear coat can be baked in a shop and be as durable as the manufacture's clear. no way.

most times the baked on paint from the factory is a better base than going to metal and starting over.. depends on the car..
if it's a laquer paint on a all original car, I'd go to metal.. cause if it hasn't spiderwebed(checked) it will...
got to remember mid 80's and newer are 26+ years old now..
tons of these are getting rodded, as most don't have the green for the 64-72 cars,, or s 32-34 ford.. 55-57 etc..
myc-10(71) will go to metal, as the new paint buy the p/o (2000) lifted the oem paint, but not the primer under it.. no idea what gm used on trucks in 71 (enamel??) but the mid line duport pulled it up.. 30 years later.. if it was the new paint only lifting, I'd say p/o prep was the cause.. but it pulled the factory paint.. no sealer was used as far as I can tell.. from a d/a and feathering a spot

Thank you for explaining the acronym (P/O)

are you sure that the previous paint didn't delaminate from the original primer as the OEM has had trouble with adhesion for for decades?

Tech 69...please explain the difference between OEM baking of factory finished paint versus you or I taking a vehicle down to bare metal, properly prepping it, applying base coat, allowing it to flash, clearing it and then running a bake cycle for the recommended time and temperature. Do they use better material from Dupont. PPG etc., do they have better heat? Do they bake it longer? The only major difference that I'm aware of is the "E-coat". However, the E-coat has been blamed for much of the delamination that the OEM has experienced over the years. I'm interested in understanding what the the OEM does that the aftermarket is lacking.

I wouldn't be afraid to put a paint job that I did on a vehicle beside an OEM finish and with all being equal, I would stand behind mine much more readily than the OEM finish. Overall, I'd say that the aftermarket has had a better track record with respect to durability than any of the major auto manufacturers.

are you sure that the previous paint didn't delaminate from the original primer as the OEM has had trouble with adhesion for for decades?

Ray

from what I can tell.. the new(er) paint/primer and original color coat lifted and peels like mid 80's fords, take a razor to it, and it comes off like it's wallpaper..lol but the original primer is not..
it's odd, to say the least.. the feathering shows one repaint.

I do not agree that a clear coat can be baked in a shop and be as durable as the manufacture's clear. no way.

You don't think a shop painted item can be more durable than the factory?
I can show you my painted bumpers compared to the factory ones,
it's quite obvious my bumpers get way less road rash, rock chips than
the factory ones. That's why I use epoxy primer on them.
It's a big difference that my customers really like.

from what I can tell.. the new(er) paint/primer and original color coat lifted and peels like mid 80's fords, take a razor to it, and it comes off like it's wallpaper..lol but the original primer is not..
it's odd, to say the least.. the feathering shows one repaint.

That is the problem that the OEM has had for decades. The cars where originally painted wet on wet,the original primer applied to the metal rarely failed, it was the color coat on top of the primer that had issues and it is the belief of some people in the industry that the original "primer coat" was left to flash to long before the color coat was applied. Now is this what happened, I'm not sure, I wasn't there but, the explanation does sound reasonable. The early wet on wet primers had a much tighter window than the primers (Epoxy) that we have in the aftermarket today. From the OEM standpoint, they didn't have the time (to labor intensive) to ensure for mechanical adhesion between primer and color, that's why they used the wet on wet system.

This isn't all bad though, because of the adhesion problem seen from OEM paint work, we have evolved to Epoxy primers today giving us extended windows for top coating before the need for sanding, some up to 7 days, this time frame would have been unheard of 20 to 30 years ago. By the way, maybe I'm old school, but, I still prefer to give primers the benefit of sanding, just to give it both the chemical and mechanical adhesion characteristics that allows paint to stick.

You don't think a shop painted item can be more durable than the factory?
I can show you my painted bumpers compared to the factory ones,
it's quite obvious my bumpers get way less road rash, rock chips than
the factory ones. That's why I use epoxy primer on them.
It's a big difference that my customers really like.

I agree with you, baked clear or unbaked clear. Unbaked clear will cure to the same level of hardness over time as baked clear. The reason for a bake cycle is productivity and nothing else. If the OEM could keep the assembly line moving as fast without a bake cycle they would implement that procedure immediately as would any Body Shop. The cost of running a bake cycle is extremely high and insurance companies sure don't pay extra if you have that cycle.

One reason your bumpers with stand rock chips better than OEM is the epoxy primer, Epoxy is much more flexible and creates a cushion between the plastic and the top coat.

What we do at the body shop is more of a "forced dry" at 140 or so. While at the manufacturer I believe they get much hotter as the car is painted before it's assembled, I believe it's more of a real "Bake" and gets into the hundreds of degrees.

In the case of a 1955 car, I would take it the car down to bare metal or I wouldn't touch it, zinc primer, how little surface rust there is under the original paint/primer....I don't want to get picky but you yourself said how "little" surface rust is under the areas with original paint/primer....then it's not surface rust...it's rust underneath...the car is 58 years old...if there's a little rust...it's got to be cleaned up or it will come through. Products today are much more apt to minimize rust than they where 50 to 60 years ago, wouldn't you agree? Why, when doing a restoration would you want to start a foundation on 60 year old technology?

I never said that I'd ever agree to go over the paint on that job. I just said it's an example of how a repair done later had more surface rust.

What we do at the body shop is more of a "forced dry" at 140 or so. While at the manufacturer I believe they get much hotter as the car is painted before it's assembled, I believe it's more of a real "Bake" and gets into the hundreds of degrees.

Brian

yep. Due to the rubber and plastic in the car it can't be done in a shop.

I will say, I thought that the OEM gave up the high temperature paint cure with the major peeling problem that they had into the 90's...so I called a friend of mine who would know and this is what I was told.

"In the 70's they used to bake paint at 350 degrees to achieve cross linking...they found out it didn't work well. In the 80's with start of base clear in North America is when they started experimenting with different ways to achieve cross linking at lower temperatures and a more widespread use of catalysts...they found out it didn't work well. Today with the 1K Melamine clears, being baked at 285 degrees they are having a similar situation...it's not working well. Manufacturer's are still paying out claims for delamination at a higher rate than the aftermarket repair shop has claims for adhesion. Consistent adhesion at the OEM level is still an issue and time will tell."

I do apologize, I thought that the ultra high temperature clear bake went away when water born base coat was introduced and more widely used at the OEM level.

However, I will stand by what I said earlier, I will put a paint job done from metal up by a qualified experienced painter ahead of an OEM paint job any time. I know I would get a better finish (less orange peel) I know that the aftermarket has a lower number of adhesion issues than the OEM and because they bake their clear at a high temperature and have done so for many previous years of failure, I don't believe it makes it better...probably faster, but not better.

As far as removing OEM primers on collision repairs, I agree with you Tech69, if it's not necessary to do the repair back to OEM standards, then there's no need. If I'm doing a restoration on an old vehicle with old paint...it's coming off. Not many people are restoring a 13 year old Jetta, but aftermarket clear coat being durable with fewer adhesion problems...in a heart beat...and isn't adhesion part of durability.

Ray

The Following User Says Thank You to 69 widetrack For This Useful Post:

I will say, I thought that the OEM gave up the high temperature paint cure with the major peeling problem that they had into the 90's...so I called a friend of mine who would know and this is what I was told.

"In the 70's they used to bake paint at 350 degrees to achieve cross linking...they found out it didn't work well. In the 80's with start of base clear in North America is when they started experimenting with different ways to achieve cross linking at lower temperatures and a more widespread use of catalysts...they found out it didn't work well. Today with the 1K Melamine clears, being baked at 285 degrees they are having a similar situation...it's not working well. Manufacturer's are still paying out claims for delamination at a higher rate than the aftermarket repair shop has claims for adhesion. Consistent adhesion at the OEM level is still an issue and time will tell."

I do apologize, I thought that the ultra high temperature clear bake went away when water born base coat was introduced and more widely used at the OEM level.

However, I will stand by what I said earlier, I will put a paint job done from metal up by a qualified experienced painter ahead of an OEM paint job any time. I know I would get a better finish (less orange peel) I know that the aftermarket has a lower number of adhesion issues than the OEM and because they bake their clear at a high temperature and have done so for many previous years of failure, I don't believe it makes it better...probably faster, but not better.

As far as removing OEM primers on collision repairs, I agree with you Tech69, if it's not necessary to do the repair back to OEM standards, then there's no need. If I'm doing a restoration on an old vehicle with old paint...it's coming off. Not many people are restoring a 13 year old Jetta, but aftermarket clear coat being durable with fewer adhesion problems...in a heart beat...and isn't adhesion part of durability.

Ray

no one could afford a car if they rub'd on it like a resto.. come on..
what few claims they get, they make up in time.. they bet the horse it'll outlast the warranty or get hit.. or better yet totalled..
with 16 air bags it don't take a hard hit to total cars anymore..
I'm shocked that my 26y/o and 28y/o cars look as good as they do.. as the paint on it,todays macco's bottom junk is better product.. than the crap they sprayed in the 80's.. in the oem.. both are tired but still shine. somewhat..lol

no one could afford a car if they rub'd on it like a resto.. come on..
what few claims they get, they make up in time.. they bet the horse it'll outlast the warranty or get hit.. or better yet totalled..
with 16 air bags it don't take a hard hit to total cars anymore..
I'm shocked that my 26y/o and 28y/o cars look as good as they do.. as the paint on it,todays macco's bottom junk is better product.. than the crap they sprayed in the 80's.. in the oem.. both are tired but still shine. somewhat..lol

I feel that people assume that a new vehicle is perfect and don't spend enough time looking at the paint, or don't know what to look for. They do seem to be more critical of the finish after a repair than they are with a factory finish. I have cut and buffed numerous new vehicles, mostly to get rid of the factory orange peel and in some cases re-cleared a new vehicle before I cut and buffed it. The OEM has set their standards so low when it comes to finish, what is being accepted by the buying public is also lowered. (If every manufacturer is putting out poor finishes and you want a new vehicle, what do you do?).

As you mentioned that it doesn't take much to write off a vehicle today because of air bags, expensive parts and just the fact that vehicles are made to crumble on impact instead of withstand an impact for safety, does write of many relatively new vehicles. I agree that they do look after a certain number of vehicles for paint problems under warranty, but, generally there needs to be a call back before a manufacturer warranties the paint. How many people paid out of pocket to get their vehicles painted in the nineties when Ford had the massive recall on paint? I know I painted my fair share and the customer paid.

Martin Senour products ARE Sherwin Williams. Not just "made by" Sherwin Williams, we are talking exact same product with a different label on the can, same batch code, same exact product.

But this is all a moot point because the products that are used in production aren't even available to repair shop or anyone else as a rule. They are applied in a way that no repair shop could apply it, they are different products.

The manufactures have accepted products that they recommend, from every manufacturer who has spent the time and money to get that ok. When I was a rep for MS I had a book with all the products oked by the big manufacturers like GM and Ford, a list of Dupont, S-W (MS) PPG, Sikkens, products.

Now, that all being said, applying a PPG primer over the OEM Dupont paint isn't a problem at all. Even applying your Dupont paint over the PPG paint that was painted on you car 10 years ago after an accident. That really isn't an issue at all.

Applying a product over a different manufacturers fully cured product isn't a big deal, it's insoluble (if it's a good product) It's when you are asking the products to intermix, like a clear over another brand of basecoat, that is a HUGE no-no. The base isn't fully cured or dried even, and you are applying another clear over it, not good.

If you are mixing products, what tech sheet do you follow?

HOWEVER, you "can" do it, hell yes you can.

Pro's who know WHAT these products are can get away with it, for instance you are spraying a paint over an epoxy primer of a different manufacturer you follow the tech sheet on the epoxy primer and then you follow the paint's tech sheet as it may refer to spraying over THAT companies epoxy primer. This isn't "that" big of a deal, but it is opening up the door a little bit for trouble.

Your typical quality shop is going to use the same products start to finish, they have a warranty provided by that company BECAUSE they are using all their products. The painters have been trained by them, their products are all that is in the shop, and for this they get a life time warranty like at the shop I work at.

Does it mean the shop isn't a good shop if they mix some products, no not at all. But as a rule, as a rep, funny things often happen in those shops, we called them "Junior chemists" and they had problems, OFTEN. It wasn't so much that they used a different primer or something, it was that they were VERY open to making their own rules, the different primer by it's self wasn't a issue, it was that opened a door, that was just an example of the other hair balled things they did.

If you want to eliminate issues, if you want your project to go as smooth as you can, you stick with all the same products as they are suggested on the tech sheets.

For the home hobbiest, follow the tech sheets, use all the same products from one line and you are going to be WAY better off.

Brian

Brian,AS much as I do respect your talents and knowlage I just cant let this one slide by ...Excuse my lack of diplomatic wording and sentance structure..

Well if no one else will say it I guess I will......COMPLETE B.S.
When I read this crap it sounds like youve never stepped foot in a body shop ,EVER...
You can put ANY base over ANY primer ANY clear over ANY base..thats the long and short of it....
What you dont want to do is use reducer or hardener in an other brands primer, base or clear thats where the trouble can start... As long as each uses its own system it'll be fine ,Thats how we get the best of the best materials with fantastic results...
In all my years of actually working in a shop (many shops) nobody sticks to all One brand ,thats rediculas ,not even the shops that sign a contract with PPG only to use thier products, use only PPG..... we want the BEST bondo, primer for the money and the all BEST materials to get the best work and its just not possible from one brand ....sure You can "get away with it",using all one brand, but it wont be the BEST you can do...I really feel sorry for the ones that actually believe this crap but I do understand how confussing it can be and how playing it (somewhat) safe seems like a good idea and thats what these big paint companies want you to think... Dupont chroma base even tried to make it true with their basemaker reducer ,you'll have problems using anything else but as long as you use the basemaker spraying it over any primer and using any clear isnt a problem....
Just tellin it like it really is...Sorry

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.

User Name:

Password

Please enter a password for your user account. Note that passwords are case-sensitive.

Password:

Confirm Password:

Email Address

Please enter a valid email address for yourself.

Email Address:

Log-in

User Name

Remember Me?

Password

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.